Stimulants are substances that all result in the increase of levels of dopamine in the brain, which is a neurotransmitter that affects attention and pleasure. What this means is that stimulants affect our brain and the way it works by changing the ways that nerve cells communicate.
Neurons (nerve cells) are the cells that have a role in transmitting messages from the brain to other parts of our body, and vice-versa, which is important for pain response, alertness, energy etc.
With long-term use, the use of stimulants would affect the central nervous system (speeding it up), the brain, and the functions necessary to live, like respiration, heart rate, blood pressure, body temperature. Levels of neurotransmitters like dopamine, serotonin, and GABA, which are responsible for the regulation of different processes, are also impacted, which creates a chemical disbalance ultimately resulting in behavioral changes, mood swings, altered attention, movement and energy, stress etc.
So the part of the body that is affected the most with the long-term use of stimulants like cocaine, nicotine, methamphetamine is the brain of course, which is where these substances have the most impact, but the impact on the central nervous system, autonomous nervous system, and neurotransmitter levels is significant.
The correct answer is RNA polymerase does not require a primer to add new nucleotides.
Explanation:
RNA polymerase is an important enzyme of transcription process that deals with the formation of mRNA from DNA. unlike DNA replication, transcription process does not require any RNA primer to carry out the synthesis of mRNA in 5'→3" direction.
RNA polymerase use coding strand of DNA molecule as a template to synthesize new mRNA molecule from that parental DNA molecule.
The factors that affect personal health that are the most easily controlled are c) lifestyle. You can easily change the way you are living, whereas these other things cannot be.
It totally depends upon whether modification is being done in somatic cells or germ cells. Somatic cells modification is ethically accepted because it doesn't pass from one generation to another generation but germline modification is considered as unethical because the modification will pass on to the next generation leading to the persistence of modification in future generations. The problem with genetic modifications is that the impacts of modifications are unpredictable, rather than being fruitful they may lead to lethal mutations so if it occurs in just somatic cells, then even if it is lethal/harmful, it will be confined to only that individual but if a lethal mutation occurs in germ cells then it will pass on to the subsequent generations and it will persist in all future generations.